Safety device for centrifugal machine baskets and spindles



Jan. 1, 1929.

v A. F. DUNSMORE SAFETY DEVICE FOR CENTRIFUGAL MACH'INE BASKE AND SPINDLES Filed Jan. 19. 1928 2 Sheets-Sheet R e m M 8 0 N 4 a 2 G 5 n b 6 II E u F v.0 B 7 N f m N A 0 2 M 3 W L m a m. G 5 a a l v m 2 Jan. 1, 1929. 1,697,110,

" A. F. DUNSMORE SAFETY DEVICE FOR CEQTRIFUGAL MACHINE BASKETS AND SPIIjDLES Filed Jan. 19, 1928 2 Sheets$heet 2 6 I 0 o o 4 o Q Q 0 o o o o o aw 23 a I 30 2 2"" 29 Q22 L 2 I3 T l! 4 6 5 I 0 H I 7!"! Q H /NVENTOR. A/TDammore Patented Jan. 1, 1929 UNITED STATES 1,697,110 PATENT OFFICE.

ALEXANDER FRASER DUNSMORE, OF GLASGOW, SCOTLAND.

SAFETY DEVICE FOR CENTRIFUGAL MACHINE BASKETS AND SPINDLCES.

Application filed January 19, 1928, Serial No. 247,980, and in Great Britain December 23, 1927.

This invention, which may be regarded as a further development of that described in the prior specification 1,539,772, relates to electrically driven centrifugal machines and the like, more particularly to that class of machines known as hydro-extractors, whether of the suspended type or the pivoted type, and has for its object to provide an improved safety device for use in connection with the usual monitor case cover contrived to prevent access to the basket and spindle so long as these are rotating, even at low speed, and to prevent transmission of motion to the basket so long as the'cover is in open position or in partly open position.

In accordance with the invention there is associated with the switch or motor controller for the electric motor and the monitor case cover and shaft guards an interlocking device or the like, which, when the switch or controller is at current on position, locks the monitor cover against opening and, conversely, prevents movement of the switch or con troller to current on position .while the monitor case cover is open.

In the accompanying drawings which illustrate a hydro extractor of the suspended type according to the invention Fig. 1 is a fragmentary front elevation; Fig. 2 is a part elevation part vertical section at right angles to Fig. 1; Fig. 3 is a part plan part horizontal section; and Fig. 4 is a fragmentary rear perspective view of the machine showing the monitor case cover in closed position.

As shown, within a stationary monitor case 1 is located a rotatable basket 2 (Fig. 1) secured to a vertical driving shaft 3 assumed to be operatively connected to an overhead electric motor (not shown).

Hinged at 4 on opposite sidesof the top of the monitor case 1 are cover halves 5, 6 concentric with semi-cylindrical walls 7, 8, which, when the cover is in closed position, surround, with clearance, the shaft 3.

Semi-cylindrical guards 9, 10 contrived to surround the shaft 3 are secured at their upper ends to spindles 11, 12 pivotally connected to a plate 18 sustained by brackets 13- depending from the superstructure 14. The guard halves 9, 10 when in lowered position embrace the walls 7, 8, the arrangement being such that the guard halves must first be swung upwards before the cover halves 5, 6 can be lifted into open position.

Lugs 15 secured to the monitor case 1 sustain the cover halves 5, 6 when the latter are in open position.

Pinions 16, 17 keyed to the guard spindles 11, 12 mesh with racks 18, 19 formed, respectively, on the upper and lower edges of a horizontal bar 20 joggled at 21 intermediate the pinions and slidably moun'ted'in spaced brackets 22.

Depending from the superstructure '14 is a switch or motor controller 23 (Fig. 4) of which the operating handle 24 fixed to the spindle 25 also applies and releases the brake and may occupy any one of three positions, namely, current on, current off and brake on. Fixed to the end ofthe spindle 25 remote from the handle 24- is a pinion 26meshing with a vertically slidable rack" bar 27 the lower end 27 of which is located adjacent to the horizontal bar 20 and which is adapted,

when the switch 23 is at on-position, i. e., with the handle 24; in 1 position to obstruct the path of a lug 28 secured to the bar 20 whereby said bar 20 is locked against sliding movement in the direction to open theguards 9, 10 as shown in Figs. 1 and 4:.

The guard halves 9, 10 being interconnected through the pinions 16, 17 and the racks 18, 19 on the bar 20, it will be understood that when said bar is locked, i. e.,when the switch is at on position, it is impossible to open the monitor case cover, since it is necessary to swing the guards 9, 1O upwards before the cover halves 5, 6 can be lifted.

When the switch or controller handle 24 of the motor is in the brake on or lowest position, the guards 9, 10 and the core halves 5, 6 can be opened or shut as desired, but if the guards 9, 10 are in the open position, the horizontal bar 20, being interlocked with them is so positioned that the lug 28 on the horizontal bar 20 obstructs the downward movement of' the vertical bar 27, making it impossible to put the current on to start the machine until the cover and guard are completely closed.

To ensure that the cover cannot be opened unless or until the basket is substantially at rest, a cam 29 is fixed to the boss of the brake drum 30 secured to the shaft 8. Positioned opposite said cam is a spring-urged plunger 31 slidably guided in a bush 32 secured to one of the brackets 13. The inner end of the plunger 31 presents a head 31 adapted to be projected into the path of the cam 29 and normally held out of engagement therewith by a spring 33 embracing the plunger 81 and interposed between the guide bush 32 and a knob 34 secured to the outer end of the plunger. A latch 35, pivoted at 36 and oper atively connected at 3? to the plunger 31, engages in the lowered position of the guards, arms 38 secured to the ends of the spindles 11, 12 remote from the pinions 16, 17. It will be seen that, to open the monitor case cover, it is first necessary to depress the plunger 31 to unlatch the arms 38; if, however, the motor and therewith the basket 2 is rotating, depression of the plunger 31 to the extent necessary to unlatch the arms 38 is impossible since the cam 29 in its rotation engages the plunger and forces it back to inoperative position before unlatching can take place; only when the basket is substantially at rest with the minor axis of the cam 29collinearwith the plunger can the plunger be depressed and the guards 9, 1O lifted to clear the cover 5, 6.

A catch 39 pivoted at 40 and engageable with either guard 9, 10 serves to retain the interconnected guards 9, 10 in uplifted position as shown in Fig. 1.

When the controller 23 is in off position with the cover halves open, the lug 28 on the bar 20 is positioned directly in the path of the end 27 of the vertically slidable rack 27 whereby the controller is interlocked with said bar 20 and it is impossible to energize the driving motor until the guards 9, 10 are lowered, it being evident that to lower the guards 9, 10 it is first necessary to close the cover halves 5, 6 which in uplifted position obstruct the guards 9, 10.

What I claim is:

1. In a motor driven centrifugal machine, in combination with a spindle, a basket on said spindle, a controller for the motor, covers for the basket and for the spindle, and members operatively connected to said con troller and to said covers and movable into interfering relation with'one another to prevent movement of said controller to on position in the open position of said. covers and to prevent opening movement of said covers while" said controller is in on position.

2. Ina motor driven centrifugal machine, in combination with a spindle, a basket on the spindle, a controller for the motor, covers for the basket and for the spindle, and rackbars operatively connected to said controller and to the spindle covers and movable into interfering relation with one another to prevent movement of said controller to on position in the open position of said covers and to prevent opening movement of said covers while said controller is in on posi tion.

3. In a motor driven centrifugal machine, in combination with a spindle, a basket on the spindle, a controller for the motor, pivoted spindle-covering elements, means for latching said elements in open and in closed position, pivoted basket-covering elements adapted to be opened in the open position of the spindlecovering elements and to" obstruct the closing'niovement of the spindle-covering elements, a latch-releasing device, members o-peratively connected to said controller and to said spindle-covering elements and movable into interfering relation with one another, and a cam on the spindle preventing effective operation of the latch-releasing device during rotation of the spindle.

In testimony whereof I have signed my name to this specification.

ALEXANDER FRASER DUNSMORE. 

